As society incorporates more and more highly collaborative systems into its infrastructure, the integrities of such collaborative systems need to be maintained at constant highs. With the proliferation of global navigation satellite systems (GNSS), the world has benefited from the widely accessible precision timing and positioning services brought by GNSS that drives a good portion of the world's communication, financial, power grid, air transportation, security, and defense infrastructures. The ever greater reliance and trust placed upon the GNSS infrastructure leads to growing concerns with regard to unintentional and intentional abuses of the system. For example the future air transportation system such as FAA's NextGen Air Transportation System and European's Single European Sky ATM Research (SESAR) rely on aircrafts cooperatively reporting their GNSS positions in the clear without any encryption through a system known as Automatic Dependent Surveillance-Broadcast (ADS-B), such that unintentional incorrect position reporting (system error) or intentional spoofing (fake position reports) may damage the integrity of the system, causing significant degradation in operational safety and eventually paralyzing the air traffic management system.
Further, for encrypted GNSS position information (such as Mode 5, military equivalent of ADS-B), there is a growing concern regarding the soundness of the protection provided by the cryptology as the speed of attacks increases rapidly each year. An undetected tainted or spoofed position report creates incorrect position information which may not only lower the chance of success of an operation but also may endanger the welfare of participating units.
A couple of examples of where GNSS transceivers are often used for collecting valuable time and position-sensitive information that influences decision making process and/or assists ongoing operations are police and military operations. Another example is any information, record, or database that is crucial to security, such as on-line transaction records, may need stronger protections from malicious alterations as a result of external and internal security breaches.
Currently, to verify a reported GNSS position, an independent surveillance system is required that can provide position observations on the reporting party. For example, in order to verify an aircraft position in the ADS-B system, conventional radar surveillance systems or wide-area multilateration (WAM) surveillance systems are currently utilized. For GPS-enabled mobile devices, the existing cellular, WLAN, WiMax or other multilateration capabilities in the wireless communications infrastructure are used for providing independent position estimates to verify the positions reported by GPS-enabled mobile devices. These surveillance systems are outside of GNSS signaling framework (i.e., out-of-band) and suffer from disadvantages of incomparable coverage and accuracy to GNSS-based systems. In addition, these out-of-band surveillance systems require large infrastructure investments and present significant challenges for integrating and managing multiple systems with different accuracies.
What is needed is a system and method that can verify that accurate positions are being reported by GNSS equipped platforms and can perform the position verification within the GNSS signaling framework and infrastructure (i.e. in-band) in a highly integrated and precise fashion to provide seamless coverage without the need for independent surveillance systems.